Regenerator-furnace for use of natural gas



(No Model.) l

T. G.KIRKPATRIGK.

RBGBNERATOR PURNAGE PoRfUsB of NATURAL GAS. No. 308,565. Patented Nov.l25, 1884.

NITED `STATES 4PATnNr OFFICE.

THOMAS G. KIRKPATRIOK, OF LEEOHBURG, ASSIGNOR TO HIMSLF, AND JOHN O.KIRKPATRIOK, OF PITTSBURG, PENNSYLVANIA.

REGENERATOR-FURNACE FOR USE OF NATURAL GAS.

SPECIFICATION forming part of Letters Patent No. 308,565, dated November25, 1884.

Application filed December 24, 1853.

and I do hereby declare the following to be a full, clear, andexactdescription thereof.

Ihave discovered a method whereby natural gas, by which I mean thecarbureted-hydro- 'gen gas obtained from the earth, may be used withsafety and with great advantage in steelmaking furnaces and otherfurnaces employing gaseous fuel.

The great obstacle to the use of natural gas in gas-furnaces arises fromthe fact that a mixture of hydrogen with half its volume of oxygen ishighly explosive when heated to the required temperature for theircombination; but I have discovered that by mixing with, the natural gasa small proportion-say about one per cent-of atmospheric air, themixture may be safely ignited within the furnace without producingexplosion, and may then be conducted in a condition of slow combustionto the working-chamber of the furnace, where it is united with a currentof highly-heated air, a vivid combustion and intense heat beingproduced. rlhis discovery forms the subject of another application forLetters Patent of even date herewith, Serial No. 115,435, my presentinvention consisting in a modified construction of the gas-furnace knownas the Siemens Regencrater-Furnace, by which natural gas may be usedwith great advantage. This modification consists, mainly, insubstituting a gaschamber for the usual gas-regenerator, and providingsaid gaschamber with a valved airport, to permit a small per cent. ofair to enter the gas-chamber to support low combustion in said chamberprior to the complete combus! tion which takes place on the hearth,where the preheated air from the air-regenerator meets the gas issuingfrom the gas-chamber. A secondary feature consists in combining with theair and gas reversing-valves a reversing-valve for controlling thesteamways. lThere are also other details, which will hereinafter morefull appear.

In the accompanying drawings, Figure 1 is (No model.)

a transverse vertical section of a regeneratorfurnace for manufacture ofsteel constructed with my improvements. tal section through w x ofFig. 1. Figs. 3 and 4L are representations of nozzles for steamtuyeres.

Fig. 2 is a horizon- The drawings represent a Siemens openhearthregeneratoriurnace of'ordinary construction, excepting in theparticulars pointed out in this specification.

A is the hearth or working-chamber of the furnace. a are the hot-airpassages from the regenerator to the working-chamber at one end of thefurnace, and a at the other end. Z and b are the gaspassages to theworkingchamber at opposite ends of the furnace. B B are a pair ofair-regenerators of ordinary construction,communicating with theair-passages a and c, respectively. The air and gas passages a and b andc and b' are placed side by side, as shown in Fig. 2, the air-passagesopening into the workingchamber preferably at a higher level than thegas-passages. There are no gas-regenerators used, and in case ofaltering an existing Siemens furnace to use my improvement the ,gasregenerators are covered over by a slab or tile of fire-brick, c, so asto leave the gas-chambers C G. Into these gas-chambers C C openings d dare made for the admission of air into the chambers O G. rlhese openingsd d are furnished with a slide or register, e c, by which the'amount ofair admitted may be regulated with exactness. Air is admitted throughthe pipes ff int-o the bottom of the regenerators B B', withfthe upperends of which the air-passages a c communicate. Natural gas isintroduced through the pipes g g into the chambers C O, whichcommunicate directly with the gas-passages b b. Tuyeres j j, foradmission of steam and air, are introduced through the openings in theside walls of the furnace, so that the mouth of the tuyeres opens intothe` passages h Vlz', through which the air enters into theworking-chamber. Tuyeres z'z" are also inserted into the crown of theworking-chamber, which tuyeres point downward and inward, as shown inFig. 1. These tuyeres are made of pipe about one and one-half inch indiameter, witha piece of steam-pipe inserted conoentrically through IOOthe first-named pipe, so as to leave an annular space for the passage ofan induced current of air. 'Ihe steam-pipeis drawn down at the innerextremity to an orifice of oneeighthinch diameter, as shown in Fig. 3,or is perforated with a series of fine holes, as shown in Fig. 4. rlhesetuycres all communicate with the steam pipe 7c from a steam -generatorthrough a valve-chest, a. (Shown in Fig. 2.) In like manner thegas-pipes g g communicate with the valve-chest m, and the air-pipes f fwith the valve-chest Z. Air enters the valvechest Zthrough openings 1'r', or one end of the valve-chest may be left open. The valvechest mcommunicates with a pipe leading the gas from the gas-well orgas-holder. rllhe three valve-chests Z, m, and n may be placed side byside, as shown in Fig. 2, so that all the valves may be opened on oneside and closed on the other side simultaneously by means of the leverq, Fig. 1. The valves s s in the gas and steam chests m and a aremushroom-valves seating into valve-seats at the ends of the pipes g gand 7s k', which open into the valve-chests. Each pair of valves isplaced on one stem, so that when one valve of the pair is open the othervalve is closed. The valve in the airchest Z is a butterflyreversing-valve, t, such asis ordinarily used in connection withregenerators, so that turned in one direction it opens the communicationbetween the outside air andthe regenerator B, and at the same time opensthe communication between the other regenerator, B, and the flue leadingto the chimney. rIhe butterfly-valve t is pivoted to a horizont-alshaft, a, which shaft is operated to reverse the valve by means of thelevers qq',- and thehorizontal shaft u is also connected by short linkst to the stem of each of the mushroom-valves s s', 85e., so that theyare opened or closed as and when the butterflyvalve t is shifted. 3ythis arrangement,when the butterfly-valve t is shifted so as to connectthe regenerator B with the air-flue, and open the communication betweenthe regenerator B and the chimney, valves s S open communication betweenthe gas-chest m and the chamber C, and between the steam-chest a and thesteam-pipeleading to the tuyeres j and i, and shut the correspondingvalves, s and s', thereby closing the connection between the gas-chamberC and the gas-chest, and between the steampipes which supply steam tothe tuyeres j and t" and the steam-chest.

The operation of this furnace is as follows: Vhen the valves are in theposition j ust stated, air enters the regenerator B, and, being highlyheated in traversing it, passes up the air-passage a, (which isalongside of the passage b,) and to a point near the roof of thefurnace, at a, where it meets a stream of air and steam, (or superheatedsteam, if preferred,) and enters the working-chamber therewith. At thesame time the natural gas flowing through the pipe g enters thegas-chamber C, where it is mixed with small currents of air enteringthrough the openings el, and, being there ignited, (by

means of a taper introduced into the chamber C, or by means of a smallgas-jet inside the chamber C, which is always supplied with gas and keptburning,) the burning Vgas ascends the gas -passage b and enters theworkingchamber below the inflowing currents of hot air, causing a vividcombustion and intense heat. Streams of mingled steam and air also enterthrough the tuyeres t', (placed on opposite sides of the furnace, asshown in Fig. 2,) and aid the combustion and produce a swirling motionof the flame within the workingchamber.

IVhen it is desired to charge the furnace, the regenerator B having beencooled by the inflowing air and the other regenerator heated by theoutilowing products of combustion from the working-chamber, the lever qis shifted, which shifts the butterfly-valvet and closes the valves s s,opening the Valves s s', and thus causes the air to pass throughregenerator B', and the gas through chamber C', and the products ofcombustion through regenerator B, thus reversing the direction of allthe currents.

I do not desire to confine my invention to the use of the particularkind of reversingvalves for gas and steam in combination with the pairof regenerators and of gas-chambers, as the ordinary kind ofreversing-valves may be employed.

Having thus described my improvement, what I claim as my invention, anddesire to secure by Letters Patent, is-

l. In a furnace for burning gaseous fuel, the combination, with aworking-chamber, of two gas-chambers, each having an air-port foradmitting air thereto, iand a port or passage delivering into theworking-chamber, two airregenerators, each having a port or passagedelivering into the working-chamber adjacent to the gas-discharge of thecorresponding gaschamber, and reversing-valves, substantially as and forthe purposes specified.

2. In a furnace for burning gaseous fuel, the combination, with aworking-chamber, of two gas-chambers, each having an air-port foradmitting air thereto, and a port or passage delivering into theworking-chamber, two air-regencrators, cach having a port or passagedelivering into the working-chamber adjacent to the gas-discharge of thecorresponding gaschamber, steam-jet pipes arranged to deliver into thehot-air passages leading from the airregenerators, and three sets ofreversingvalves, arranged to control the air, gas, and steam supplies,substantially as and for the purposes specied.

3. In a furnace for burning gaseous fuel, the combination, with aworking-chamber having air-ports, and steam-jets arranged in saidairport-s, of two gas-chambers, each having an air-port for admittingair to the gas-chamber, and a port or passage delivering into theworking-chamber, two air-regenerators, each having ports or passagesdelivering into the working-chamber adjacent to the gas-discharge of ICOIIO

welve, substantially asgmd for the purposes 1o specified.

In testimony whereof I have hereunto set my hand this 17 th day ofDecember, A. D. 1883.

THOMAS G. KIRKPATRICK.

W'itnesses:

W. BAKEWELL, W. B. CoRWIN.

